Throttle valve mechanism



Aug. 15, 1944. Q ALLEN I THROTTLE VALVE MECHANISM Filed Aug. 28. 1942 INVENTOR Ra dill/law. BY

Hi5 ATTORNEY.

mm STAT to such tools.

only a small amount of throttle valve in general; by and is Patented Aug. 15, 1944 THROTTLE vALvaMEcnA'msM 2,

Roy Athens, Pal, .-.Rand Company, New Y tion 01 liew Jersey assignorto .In gersollork; N. Y., a corpora- Application August 28, 1942, Serial No. 456,51s r 7 3 Claims. '(o1.277 f2o) This invention "relates to fluid actuated-tools;

and more particularly to a throttlevalve mechanism for controlling the supply of pressure fluid It is an object of the present invention to provide a throttle valve space for its accommodation in a tool to which it may be applied and which may be conveniently operated to supply pressure fluid in successive order to different 7 parts of the tool and "at thesame time to maintain adequate seals in the throttle-valve mechanism in order to prevent the wastage of power medium.

Other objects will be'in part obvio s and n part pointed out hereinafter. "In the drawing accompanying this specification and in which similar reference numerals rei'er to similarparts, n r i Figure 1 is a longitudinal view, partly broken away of a fluid actuated tool equipped'with mechanism constructed in accordance with the practice of the invention; and Figure 2 is a transverse view taken through Figure l on the line 2-2.'

Referring more particularly to th e drawing; the tooiembodying the inventionis designated,

shownasbeing in the form oi'a riveting machineofa known type comprising a cylinder 2| having a chamber 22 for the'accommodation of a power unit23 of the fluid actuated percussive type which may normally be held in the rearmost" position shown in Figure l= of the drawing by a spring (not shown) in the front end of the cylinderfl.

As is customary in tools unit is slidable longitudinally of the chambe'r 22 and is in itself a complete unit having a hammer piston (not shown) and a suitable valve (not shown) for efiecting the distribution of'pressure unit 23, in the present instance'i isintended to actuate a rivet set 24 for upsetting a rivet 25 in work pieces 25. The head of the rivet rests in a recessed block 21 carried by a yoke 28 and the 1 yoke is attached to the cylinder 2| 'by'bolts 29.

A closure is provided for the-rearward end of the cylinder 2| in the form of'a back head30 secured to the cylinder by bolts 3|, as indicated in Figure 2 of the drawing. The back head '30 also.

has a longitudinally extending chamber 32 to ac commodate a plunger 33 that seats at its front end against the rearward end of -the power unit 23. These ends of the plunger and of the power unit constitute, respectively, pressure surfaces mechanism that requires "its percussive element.

34 and 35 against which pressure'fluid acts, in the first instance, for moving the power unit forwardly in the cylinder 2| tothe operative positionon the work and in the second case, to press the power unit'firmly against the rivet in accordancewith the upsettingthereof as well as to supply pressure fluid to the power unit for driving conveyed into the power unit by a passage, or

of this-type. the power H fluid to actuate such'hammer piston. The power e i her f th plug'fifl, nd in the back head 30 the throttle valve ject matter-of thisspecification and is accordpassages, 36 that is inconstant communication with the rearward end of the chamber 22.

The back head 3|Ja1so constitutes a housing for mechanism forming the subin l Provided with a transverse bore 31 that extends entirely throughthe back head and is threaded at one end, as at 38, for the accommodation of a sealing member 3 Within the bore 31 is a plug 40 thatmay be secured in assembled position in any. well known manner and has an axial bore'to form a valve chamber 4|, The plug 40 preferably projects a slight distance from the open end of the bore' 3! and is spaced from the sealing member where- 25 with it cooperates to define a supply chamber 42 in the bore 31 for pressure fluid. The pressure 'fiuid passes to the supply chamber 42 through a passage 43 in the back head and the outer end of the passage 43 is threaded as indicated at 44 for connection'with a conduit (not shown) leading from a source of pressure fluid supply. i

All the pressure fluld supplied to thevarious portions of the rivetingtool is taken from the supply chamber 42 and the plug 4ll'is accordingly provided with a passage 45 that opens at one end into the valve chamber 4|, at a point near the supply chamber 42, and communicates at its other end with a longitudinally extending groove 46 in the periphery of the plug 40 The'groove 46 opens"intoan"annular groove 41, also in the 'end of the chamber 32 and communicates with a passage 50, in theplug 40, opening into the innermost end of the valve chamber 4|.

Communication between the supplychamber 42 and the passage 45 is controlled by a throttle valve 5| of'the poppet type, thehead 52 of which cooperates with a seating surface 53 at thejuncture of the valve chamber 4| and the supply 7 chamber 42 ,for cutting oil the flow of pressure .,Such pressure fluid 'is r means of the lever 1|.

and associated channels. The stem 54 of the valve-| is slidable freely within the valve chamber 4| and'inlits periphery is an annular groove .55 toconvey the pressurefluidirom the supply chamber 42 to the passage 45 in the unseated position oi. the valve 5|.

The valve -:5l. ishollow throughout its length having a bore56 and in it is arranged a second valve 51, also of the poppet type, for controlling the flow of pressure fluid from thesupply chamber" to the passage 50; The head 58 of the valve 5.1 .seats against a tapered seating surface Hon the valve 5| at the end of the bore 56 and the stem 60 is of'such length that its free end projects from the end of the stem '54.

:In the periphery of the stem 50, adjacent the head 5!, is an annularqgroove il .into which pressure fluid flows from the supply chamber 42 in .the unseated position of the valve 51', and arms- :sage 82 in the stem 80 conveys such pressure fluid from the groove 8| to .a second annular groove ll intermediate the ends of the stem B0.

A passage 24 in, the stem 54 affords communication between the annular groove 03 and the innermost end of the valve chamber 4|. The annular groove 63 is of such length'that-it will remain in registry with the passage 64 in all the positions to which the valve 51 may be moved relatively to the valve 5|.

Preterablya port "is formed in the valve stem 54 to aflord communication between the grooves 55 and 8| in the closed positions of the throttle valves 5| and 51 and said valves are respectively held against their seats by springs .56 and 61 interposed between the valves and the sealing member 39.

In the form of the invention shown, the valves 5| and 51 are lifted from their seats to admit pressure fluid to the chambers 32 and 22 by a common actuating means that acts to unseat the valves in successive order. The actuating .means is manipulated by manual force and is shown as comprising a'rod i8 rotatable in lugs'59 onthe cylinder 2| and in a'bore 10 in the back head I 80. The rod. isprovidejd' with a lever'll whereby'the said rod may bearotated and the lever 1| is located between the lugs 69 and may be secured tlxedlyto the rod in any well known manner.

On the end oi the rod 58 projecting rearwardly r'irom thebore 1l| is a valve lifter 12 that may be suitably "keyed to the rod and has a wing portion .13 to oscillate through the axes of the throttle valves accordingly as the rod 58 is actuated by The movement of the valve litter is transmitted to the valves by a push I rod 14 arranged slidably ina bore 15 in the plug 40 and axially of the throttle valves.

The inner end of the push rod 14 lies within the valve chamber 4| and has a head 16 to engage the end surface of the valve chamber for retaining the push rod 14 in the plug 40. The head 16 is at all timesinpositionto engage the end of the-valve stem 60 but is of less thickness than the space normally existing between the end surfaces of the valve chamber and the valve stem '00 so that the valve 51 may rest flrmly on its seat without hindranceby the push rod.

Preferably the push rod 14 is provided with .a passage 11 that communicates at its inner end with the adjacent portion of the valve chamber 4| and has a laterally extending branch 1.8 which is so located that it will be in communication with the atmosphere when both valves are seated but will be blanked-01f by the wall of the bore the atmosphere.

8,355,599 fluid .iromthe supply chamber .to theipassage "4| 15 during the initial unseating movement 01 the valve 51.

The operation of the device is as follows: Whenever it is intended to upset a rivet 25 the valve actuator, including the valve lifter 12, is rocked inwardly towards the cylinder 2|. During the initial movement of the valve lifter the push rod 14 will first unseat the valve 51. Pressure fluid will then flow from the supply chamber 42 through the channels in the valve stem 60 and the passage. into the inner end of the valve chamber 4|, thence through the passages 50--49.into the chamber 32 and, acting against the pressure surface, will move the plunger and the power unit 23 forwardly in the cylinder 2| to place the rivet set 24 into-contact with the rivet 25, During that portion of the opening movement of the valve 51 required to move the groove 5| out of registry with the port 65 a small amount of pressure fluid will also flow through the passage 45 and the associated channels into the rearward end of the chamber 22. The amount of pressure fluid thus admitted into the chamber 32 is, howevenof insumcient volume to afford material assistance in moving the power unit forwardly or to set its distributing -and percussive elements in operation prematurely.

Upon continued movement of the valve lifter I 12 in the direction described the push rod 14 will contact the inner end of the valve stem 54 and the throttle 'valve 5| will be moved off of its seat. Pressure fluidwill then flow through the annular groove 55, the passage 45, the grooves 48 and 41 and through the passage 48 into the rearward end of the chamber 22 to act against the pressure surface 35. The pressure fluid thus admitted into the chamber 22 will assist in pressing the power unit forwardly toward the work and at the same time a portion of such pressure fluid flows through the ports 35 into the power unit for distribution to actuate the hammer piston.

After the rivet 25 has been completely upset the lever 1| is released and the springs 66 and 61 will then return the valves 5| and 51 to their seats to cut-oil the chambers 32 and 22 from the supply chamber 42. The pressure fluid in the chamber 22 will then pass through the distributing and percussive elements of the power unit to the atmosphere and such pressure fluid as may exist in the chamber 32 will return through the passages 49 and 50 into the inner end of the valve chamber 4|, whence it escapes through the passages in the push rod 14 and through the passage 64, the channels in the valve stem the port 55 and the connecting passages to the chamber 22 to pass through the power unit to In practice, the present invention has been 'found to .be particularly well suited for use in power tools in which it is desirable that the weight of the entire structure be maintained at a minimum and in which it is required to valve pressure fluid in successive order to different portions of the tool. The throttle valve structure, as may be readily observed, requires only a small amount of space and at the same time all the ports and passages in thethrottle valves and those which the throttle valves control may be conveniently located in such wise that they will be adequately sealed against leakage in the various positions that the throttle valves may occupy.

I-claim:

l, A throttle valve mechanism, comprising a casing having valve and pressure fluid supply chambers and a plurality of passages opening into the valve chamber, a pair of throttle valves for controlling the flow of pressure fluid from the supply chamber to the passages, and both throttle valves having channels registering with each other for conveying pressure fluid to one of the passages, and a common means for actuating the throttle valves successively.

2. A throttle valve mechanism, comprising a casing having valve and pressure fluid supply chambers and passages opening into the valve chamber, a pair of reciprocatory throttle valves in the valve chamber for controlling the flow of pressure fluid to the passages, there being channels in both throttle valves to convey pressure fluid from the supply chamber to one of the passages, a seat on one valve for the other valve, and a common means for actuating the throttle valves successively.

3. A throttle valve mechanism, comprising a 20 casing having valve and pressure chambers and passages opening into the valve chamber, a pair of reciprocatory throttle valves in the valve chamber for controlling the flow of pressure fluid to the passages and one throttle valve being arranged slidably in the other, there being channels in both valves for conveying pressure fluid from the supply chamber to one of the passages, a seat on the casing for the outermost throttle valve, a seat on the outermost throttle valve for the other throttle valve, and manually operated means for actuating the throttle valves movable in one direction to first unseat the innermost throttle valve to communicate the channels with the supply chamber for supplying pressure fluid to one passage and upon further movement in such direction to next unseat the other throttle valve for valving pressure fluid from the supply chamber to another passage.

ROY O. ALLEN.

fluid supply 

